Design Of Automatic Control Research Articles

2107 外乱を考慮したHDL記述の制御器の機能創発(OS10-2 創発の手法と機能創出,OS10 創発性と多様性の設計)

In this paper, a method of automatic controller design for electronic control systems considering for disturbance is described. In order to automate the design of the electronic controller, an evolutionary computation is applied. First, the framework for applying the genetic algorithm to the automation of controller design is described. In particular, the coding of a chromosome is shown in detail. Then, how to make a fitness function is represented, with an inverted pendulum as an example, and the controller of the inverted pendulum is developed automatically using our proposed framework. Finally, an evolutionary simulation is performed to confirm our framework.

Design and Implementation of Automatic Discharge Gap Controller for a Curved Hole Creating Microrobot with an Electrical Discharge Machining Function

This study deals with the development of a mechanism which can autonomously and automatically control the discharge gap for achieving electrical discharge machining (EDM) in an almost isolated space. This is so that a microrobot equipped with the mechanism can create a long, complicated curved hole, a hole that could not be formed by conventional machining methods. Holes formed by conventional machining methods are generally straight, so pipelines built in a variety of mechanical apparatuses consist of straight or polygonal lines. Such dearth of variety in realizable hole shapes can sometimes cause fundamental problems. A typical example of the problems appears in the design and production of water channels, i.e., pipelines built in metal molds to achieve appropriate thermal controls in molding processes. Specifically, the low variety of hole shapes prevents the shapes and positions of water channels from being optimized for the best thermal control in molding. Therefore, the development of a new method for machining curved holes has been needed. To meet this needed, we have conceived a method of machining curved holes by employing a microrobot that can perform EDM. A long, complicated curved hole can be created by making the microrobot perform stable EDM while moving along a long, complicated, curved trajectory in a workpiece. In order to realize this concept, the microrobot must have the capability to autonomously and automatically control the discharge gap in such an almost isolated space as the bottom or end of a curved hole. Accordingly, this study devises a new mechanism to give the microrobot this capability, and it calls the mechanism the “automatic discharge gap controller” (ADGC). The main components of ADGC are an electrode and power supply for EDM and a bidirectional actuator in which shape memory alloy (SMA) is employed. The results obtained from the experiments using a prototype of the ADGC prove that the ADGC has the capability of performing stable EDM by controlling the discharge gap autonomously and automatically without any other actuators.

Automatic Control Design for Optimal Strategy in Fed-batch Culture with Coupled Feed of Glycerol and Alkali

In this paper, we study the production of 1,3-propanediol in fed-batch culture with coupled feed of glycerol and alkali. On the basis of the numerical solution to an optimal control problem subjected to a multi-stage nonlinear dynamical system, we propose a realizable optimal feeding strategy. Correspondingly, an automatic control system is designed for the fermenter, which involves the designs of control circuit, software flow control and computer monitored control system. This contribution successfully achieves a goal of combining a mathematically theoretical analysis with an automatic control design in the laboratory.

Numerical analysis of the oscillation susceptibility along the path of longitudinal flight equilibria of a reentry vehicle

In this paper, it is shown that when the automatic flight control system (AFCS) is decoupled, then on the path of longitudinal flight equilibria of the ALFLEX reentry vehicle, there exist saddle–node bifurcations resulting in oscillations: when the elevator angle exceeds the bifurcation value, the angle of attack and pitch rate oscillate with the same period, while the pitch angle increases or decreases infinitely. Hence, the orbit of the system is spiraling. It is also shown that a mild (non-catastrophic) stability loss occurs due to the bifurcations. Based on this analysis, an automatic flight control design is developed.

On the Design of AGC Circuits in IM-DD NRZ Optical Transmission Systems

This paper presents the investigation on the design of automatic gain control (AGC) circuits assumed to be robust against both bias and swing variations in the received unipolar digital signal. We have derived a small signal AGC general model that includes the impact of all relevant AGC components on the AGC transfer function. This model has been used for the calculation of AGC loop parameters of the specified AGC transfer function. The AGC robustness against signal level transients has been improved by introducing the second-order AGC loop. In ac-coupled receivers, the order and corner frequency of high-pass filter (HPF) placed in front of the AGC have been investigated. The HPF has been designed so that the input signal bias variations caused by signal level transients are compressed in acceptable limits, and so that bit-pattern bias variations do not significantly decrease the receiver performance. Signal swing and bias variations become very critical in optical systems using unipolar modulation format. Since the AGC design depends on its application, as an example, we have presented the AGC design concept in dispersion compensating 10.7 Gb/s intensity-modulated direct-detection (IM-DD) nonreturn-to-zero (NRZ) optical receiver using maximum-likelihood sequence estimation (MLSE).

Genetic Programming for the Automatic Design of Controllers for a Surface Ship

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> In this paper, the implementation of genetic programming (GP) to design a controller structure is assessed. GP is used to evolve control strategies that, given the current and desired state of the propulsion and heading dynamics of a supply ship as inputs, generate the commanded forces required to maneuver the ship. The controllers created using GP are evaluated through computer simulations and real maneuverability tests in a laboratory water basin facility. The robustness of each controller is analyzed through the simulation of environmental disturbances. In addition, GP runs in the presence of disturbances are carried out so that the different controllers obtained can be compared. The particular vessel used in this paper is a scale model of a supply ship called CyberShip II. The results obtained illustrate the benefits of using GP for the automatic design of propulsion and navigation controllers for surface ships. </para>

Gate Regulation Speed and Transition Process of Unsteady Flow in Channel

The operation methods of channel and the speed of gate regulation have great influence on the transformation of flow in water conveyance channels. Based on characteristics method, a 1-D unsteady flow numerical model for gate regulation was established in this study. The process of water flow was simulated under different boundary conditions. The influence of gate regulation speed and channel operation methods on flow transition process was analyzed. The numerical results show that under the same conditions, with increasing regulation speed of the gate, the change rates of discharge and water level increase, while the response time of channel becomes shorter, and ultimately the discharge and water level will transit to the same equilibrium states. Moreover, the flow is easier to reach stable state, if the water level in front of the sluice is kept constant, instead of behind the sluice. This study will be important to the scheme design of automatic operation control in water conveyance channels.

Automatic Generation Controller Design in Deregulated and Networked Environment Using Predictive Control Strategy

In this paper, Generalized Predictive Control (GPC) algorithm is applied to design automatic generation control (AGC) systems in deregulated and networked environment. The proposed AGC approach can be used to deal with the effects caused by power market and communication networks. Finally, the developed scheme is implemented in a two-area AGC system, and the simulation results show the effectiveness of the proposed scheme.

Supporting VHDL Design for Air-Conditioning Controller Using Evolutionary Computation

In recent years, as part of the remarkable development of electronic techniques, electronic control has been applied to various systems. Many sensors and actuators have been implemented into those systems, and energy efficiency and performance have been greatly improved. However, these systems have been complicated, and much time has been required to develop system controllers. In this paper, a method of automatic controller design for those systems is described. In order to automate the design of an electronic controller, an evolutionary hardware is applied. First, the framework for applying the genetic algorithm to the automation of controller design is described. In particular, the coding of a chromosome is shown in detail. Then, how to make a fitness function is represented, with an air conditioner as an example, and the controller of the air conditioner is developed automatically using our proposed framework. Finally, an evolutionary simulation is performed to confirm our framework.

2113 進化計算によるハードウェア記述言語の自動生成とその制御系設計への応用(要旨講演,メカニカルシステムとその知能化)

Recent years, an electronic technique has been developing remarkably, electronics control has been applied to various control systems. Many sensors and actuators have been implemented into those systems, and an energy efficiency and a performances have been improved more than before. However the system has been more complicated on the other hand, and much time is needed in order to develop the controller of the system. In this paper, a method of automatic controller design for those systems is described. In order to automate design of an electronic controller, a evolutionaly computation is applied. First, the framework how to apply the genetic algorithm to the automation of controller design is described. In particular, the coding of a chromosome is shown in detail. Next, how to make an evaluation function is represented with an air-conditioner as an example case, and the controller of the air-conditioner is developed automatically using our proposal framework. Finally, the evolutionary simulation is performed to confirm our framework.

Designing a hierarchical fuzzy logic controller using the differential evolution approach

In conventional fuzzy logic controllers, the computational complexity increases with the dimensions of the system variables; the number of rules increases exponentially as the number of system variables increases. Hierarchical fuzzy logic controllers (HFLC) have been introduced to reduce the number of rules to a linear function of system variables. However, the use of hierarchical fuzzy logic controllers raises new issues in the automatic design of controllers, namely the coordination of outputs of sub-controllers at lower levels of the hierarchy. In this paper, a method is described for the automatic design of an HFLC using an evolutionary algorithm called differential evolution (DE). The aim in this paper is to develop a sufficiently versatile method that can be applied to the design of any HFLC architecture. The feasibility of the method is demonstrated by developing a two-stage HFLC for controlling a cart-pole with four state variables. The merits of the method are automatic generation of the HFLC and simplicity as the number of parameters used for encoding the problem are greatly reduced as compared to conventional methods.

Design and control of tensegrity robots for locomotion

The static properties of tensegrity structures have been widely appreciated in civil engineering as the basis of extremely lightweight yet strong mechanical structures. However, the dynamic properties and their potential utility in the design of robots have been relatively unexplored. This paper introduces robots based on tensegrity structures, which demonstrate that the dynamics of such structures can be utilized for locomotion. Two tensegrity robots are presented: TR3, based on a triangular tensegrity prism with three struts, and TR4, based on a quadrilateral tensegrity prism with four struts. For each of these robots, simulation models are designed, and automatic design of controllers for forward locomotion are performed in simulation using evolutionary algorithms. The evolved controllers are shown to be able to produce static and dynamic gaits in both robots. A real-world tensegrity robot is then developed based on one of the simulation models as a proof of concept. The results demonstrate that tensegrity structures can provide the basis for lightweight, strong, and fault-tolerant robots with a potential for a variety of locomotor gaits

Using direct competition to select for competent controllers in evolutionary robotics

Evolutionary robotics (ER) is a field of research that applies artificial evolution toward the automatic design and synthesis of intelligent robot controllers. The preceding decade saw numerous advances in evolutionary robotics hardware and software systems. However, the sophistication of resulting robot controllers has remained nearly static over this period of time. Here, we make the case that current methods of controller fitness evaluation are primary factors limiting the further development of ER. To address this, we define a form of fitness evaluation that relies on intra-population competition. In this research, complex neural networks were trained to control robots playing a competitive team game. To limit the amount of human bias or know-how injected into the evolving controllers, selection was based on whether controllers won or lost games. The robots relied on video sensing of their environment, and the neural networks required on the order of 150 inputs. This represents an order of magnitude increase in sensor complexity compared to other research in this field. Evolved controllers were tested extensively in real fully-autonomous robots and in simulation. Results and experiments are presented to characterize the training process and the acquisition of controller competency under different evolutionary conditions.

A Neural Network Based Automatic Generation Controller Design through Reinforcement Learning

This paper presents the design and implementation of a learning controller for the Automatic Generation Control (AGC) in power systems based on a reinforcement learning (RL) framework. In contrast to the recent RL scheme for AGC proposed by us, the present method permits handling of power system variables such as Area Control Error (ACE) and deviations from scheduled frequency and tie-line flows as continuous variables. (In the earlier scheme, these variables have to be quantized into finitely many levels). The optimal control law is arrived at in the RL framework by making use of Q-learning strategy. Since the state variables are continuous, we propose the use of Radial Basis Function (RBF) neural networks to compute the Q-values for a given input state. Since, in this application we cannot provide training data appropriate for the standard supervised learning framework, a reinforcement learning algorithm is employed to train the RBF network. We also employ a novel exploration strategy, based on a Learning Automata algorithm, for generating training samples during Q-learning. The proposed scheme, in addition to being simple to implement, inherits all the attractive features of an RL scheme such as model independent design, flexibility in control objective specification, robustness etc. Two implementations of the proposed approach are presented. Through simulation studies the attractiveness of this approach is demonstrated.

REINFORCEMENT LEARNING CONTROLLERS FOR AUTOMATIC GENERATION CONTROL IN POWER SYSTEMS HAVING REHEAT UNITS WITH GRC AND DEAD-BAND

A new automatic generation controller (AGC) design approach, adopting reinforcement learning (RL) techniques, was recently pro- posed [1]. In this paper we demonstrate the design and performance of controllers based on this RL approach for automatic generation control of systems consisting of units having complex dynamics—the reheat type of thermal units. For such systems, we also assess the capabilities of RL approach in handling realistic system features such as network changes, parameter variations, generation rate constraint (GRC), and governor deadband.

3404 進化計算を用いた室内空調装置の制御ロジックの自動設計(G1 一般セッション,未来社会を支えるものづくりとひとづくり(設計・システムから))

Recent years, an electronic technique has been developing remarkably, electronics control has been applied to various control systems. Many sensors and actuators have been implemented into those systems, and an energy efficiency and a performances have been improved more than before. However the system has been more complicated on the other hand, and much time is needed in order to develop the controller of the system. In this paper, a method of automatic controller design for those systems is described. In order to automate design of an electronic controller, a evolutionaly computation is applied. First, the framework how to apply the genetic algorithm to the automation of controller design is described. In particular, the coding of a chromosome is shown in detail. Next, how to make an evaluation function is represented with an air-conditioner as an example case, and the controller of the air-conditioner is developed automatically using our proposal framework. Finally, the evolutionary simulation is performed to confirm our framework.

Structure of the software for computer-aided logical design of automatic control

Requirements on the software for computer-aided logical design of automatic control were formulated and assumed as a basis of the software concept. According to this concept, the software for the computer-aided logical design of automatic control should have two levels: the environment of the control system designer and the (researcher) environment for development and updating of the first level. Realization of the concept was illustrated by the GAMMA-2RS system.

Effect of UV/VUV Enhanced RTP on Process Variation and Device Performance of Metal Gate/High-&amp;lt;tex&amp;gt;$kappa$&amp;lt;/tex&amp;gt;Gate Stacks for the Sub-90-nm CMOS Regime

We show that UV/VUV-enhanced rapid thermal processing (RTP) in combination with single-wafer processing using a single tool for the fabrication of metal gate/high-/spl kappa/ dielectric gate stacks not only improves overall device performance, but also leads to a significant reduction in process variation at the front end of the CMOS process flow for the sub-90-nm technology node. The gate stacks were fabricated under various UV/VUV conditions. Gate stacks processed under UV/VUV radiation during all processing steps displayed low leakage currents of the order of 10/sup -11/ A/cm/sup 2/. It is shown that the Al-Al/sub 2/O/sub 3/-Si gate stacks processed under UV/VUV conditions also display the lowest variations both in mean leakage current and mean capacitance, as compared to devices where UV/VUV was not used for all the processing steps. Therefore, it can be see that reliance on successive corrective iterations common to automatic process control or standard design simulation can be reduced significantly. As a result, UV/VUV-enhanced RTP has the potential to reduce the effect of process variations on overall device performance, thereby making the overall process more cost effective and time efficient and therefore improving yield and device reliability.

Fast ships models for seakeeping improvement studies using flaps and T-foil

Fast ships are taking a relevant role with a clear interest for military purposes. Fast sea transportation encounters several problems to be solved. This article refers to the difficulties originated by brisk vertical motions. The waves encountered by fast ships induce such vertical motions, and this has negative effects: navigation risks, sea sickness, structural damages, and load displacement. It is also interesting for military uses to stabilize the ship when an aircraft is landing or when precision firing is required. By means of submerged actuators, it is possible to alleviate vertical motions. In this research, a pair of transom flaps and a T-foil near the bow are used to counteract the waves. These actuators must move with the maximum efficiency, taking into account the dynamical characteristics of the ship. As a consequence, there is a problem of automatic control design. To carry out this design, it is important to obtain mathematical models of all the aspects involved in the problem: the ship, the waves, the actuators, and the effect on crew and comfort. The aim of this paper is to present the development of these models and the use of them for problem analysis and control design.

Automatic differentiation and nonlinear controller design by exact linearization

Various modern algorithms for controller design are based on differential-geometric concepts. A method of particular importance is called exact linearization via feedback. In this case, the implementation of the controller requires the computation of Lie derivatives, which have been computed symbolically. This can be very time consuming. We present a new computation method relying on automatic differentiation.